The main purpose of the present project is thus to quantify supraspinal central fatigue and associated changes in cortical excitability after an extreme exercise such as a mountain ultramarathon: the Ultra-Trail du Mont-blanc, by using TMS. The secondary purpose are (i) to compare neuromuscular and biological alterations induced by a mountain ultramarathon between males and females matched by age and level of performance, (ii) to evaluate, by biological urine and blood samples, the consequences of a mountain ultramarathon on kidneys and (iii) to investigate the hormonal status and bone mineral density of a group of male and female runners who take part to this type of event regularly.